The present invention relates to a manufacturing method of an inkjet head and to the inkjet head, and in particular, to a manufacturing method of inkjet heads each having a common outer dimension and a different channel characteristic and to the inkjet heads.
There has been known a shearing mode type inkjet head wherein a channel is formed on a piezoelectric substrate by grinding, an electrode is formed on a driving wall which separates the channel, and ink in the channel is jetted by applying voltage to the electrode so as to cause dogleg-shaped shear deformation to the driving wall. Among them, there has been known, for example, in Patent Document 1, an inkjet head whose productivity is highly improved because a number of head chips can be obtained in a wafer by configuring an actuator for jetting ink with so-called a harmonica type head chip where the driving wall composed of a piezoelectric element and the channel are arranged alongside alternatively and an inlet port and an out let port of each channel are provided on a front surface and a rear surface.
Meanwhile, generally, in a type of inkjet head where jetting energy is applied by causing dogleg-shaped distortion to the driving wall, an optimum drive pulse width to drive is determined by the channel characteristic. The channel characteristic is determined by a length (driving length or L length, hereinafter called L length in this specification) along a direction of ink jetting, accordingly a drive frequency is also determined. For example, in case an inkjet head required to be driven in a high frequency as a channel characteristic, L length becomes shorter, and an inkjet head having extremely short L length of 1.7 mm is being manufactured.
Also, in Patent Document 2, a channel is formed on the front and the rear surfaces of the head to be utilized for connecting the electrode.                (Patent Document 1) Unexamined Japanese Patent Application Publication No. Tokkai 2005-96414        (Patent Document 2) Unexamined Japanese Patent Application Publication No. Tokkaihei 8-30997        
In case of inkjet head having the harmonica type head chip, L length itself is a length of head chip (the length along the ink jetting direction of the channel) and because L length becomes shorter as the drive frequency becomes higher, assembling of the inkjet head becomes difficult and the strength of the head chip decreases, thus special care is needed to handle it, and a difficulty of mounting on a housing was a problem.
Also, the inkjet head is mounted on the housing using a nozzle surface as a positioning surface, if L length is changed, design of the housing has to be changed accordingly. Thus since exclusive housings are needed to be prepared for each L length, cost increase was a problem.